Abstract: Objective To investigate the clinical manifestation，diagnosis and treatment of anti-N-methyl-D-aspartate receptor encephalitis （anti-NMDAR encephalitis）. Methods The clinical manifestations， imaging， cerebrospinal fluid， polysomnography （PSG），diagnosis and treatment of 1 case of Anti-NMDAR encephalitis were reported， combined with the literature review. Results The patient had clinical manifestations such as insomnia， blurred vision， fever， abnormal sensation， and slow response， and anti-NMDAR encephalitis antibody IgG was detected in the cerebrospinal fluid，which met the diagnostic criteria of anti-NMDAR encephalitis. The patient with hormone combined with immunoglobulin treatment achieved good results. Conclusion When the clinical symptoms of anti-NMDAR encephalitis are atypical，it is easy to miss the diagnosis. Even if no abnormality is found in the brain MRI，autoimmune encephalitis detection of the cerebrospinal fluid should be detected actively. The treatment of hormone with immunoglobulin should be performed after the early diagnosis to improve the prognosis of the patient，and long-term follow-up should be carried out.

Key words: anti-NMDAR encephalitis, insomnia, cerebrospinal fluid, polysomnography（PSG）